Three-dimensional shaped article manufacturing method, three-dimensional shaped article manufacturing apparatus, ink set, and three-dimensional shaped article

ABSTRACT

A three-dimensional shaped article manufacturing method with which a three-dimensional shaped article having a matte-toned texture can be manufactured stably and efficiently is provided. A three-dimensional shaped article manufacturing method of the present invention is a method for manufacturing a three-dimensional shaped article by laminating layers formed by discharging and curing inks including a curable resin, the method including applying a substantive section-forming ink to a region that forms the three-dimensional shaped article, and applying a sacrificial layer-forming ink for forming a sacrificial layer to a region that is adjacent to a region that forms an outermost layer of the three-dimensional shaped article and on a surface side of the outermost layer, a viscoelasticity of the sacrificial layer-forming ink during curing of the substantive section-forming ink being less than a viscoelasticity of the substantive section-forming ink during curing of the substantive section-forming ink.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No.2014-002680 filed on Jan. 9, 2014. The entire disclosure of JapanesePatent Application No. 2014-002680 is hereby incorporated herein byreference.

BACKGROUND

1. Technical Field

The present invention relates to a three-dimensional shaped articlemanufacturing method, a three-dimensional shaped article manufacturingapparatus, an ink set, and a three-dimensional shaped article.

2. Related Art

Conventionally known is a method of forming a three-dimensional shapedarticle on the basis of a model of a three-dimensional object generatedwith, for example, three-dimensional computer-aided design (CAD)software or the like.

A lamination method is one known method of forming a three-dimensionalshaped article. A lamination method generally comprises forming thethree-dimensional shaped article by dividing the model of thethree-dimensional object into a large number of two-dimensionalcross-sectional layers and thereafter sequentially laminatingcross-sectional members corresponding to each of the two-dimensionalcross-sectional layers while the cross-sectional members are also beingsequentially shaped.

The lamination method makes it possible to immediately form any model ofa three-dimensional shaped article intended to be shaped, and is free ofsuch needs as creating a mold prior to the shaping, and therefore makesit possible to form a three-dimensional shaped article both quickly andinexpensively. Also, the three-dimensional shaped article is formed bylaminating the cross-sectional members, which are thin and plate-shaped,one layer at a time, and therefore it is possible to form even a complexobject having, for example, an internal structure as an integratedshaped article without dividing the object into a plurality ofcomponents.

One known form of such a lamination method is a technique for shapingthe three-dimensional shaped article while also fixing a powder with abinding solution (see JP-A-2001-150556 (patent document 1), for example.With the technique of such description, the formation of each of thelayers entails imparting color to the three-dimensional shaped articleby discharging an ink comprising a coloring agent onto a locationcorresponding to an outer surface side of the three-dimensional shapedarticle.

However, it is difficult to render finely detailed textures with theconventional methods, and in particular it is difficult to render amatte-toned texture.

SUMMARY

Aspects of the present invention are to provide a three-dimensionalshaped article manufacturing method with which a three-dimensionalshaped article having a matte-toned texture can be manufactured stablyand efficiently, to provide a three-dimensional shaped articlemanufacturing apparatus with which a three-dimensional shaped articlehaving a matte-toned texture can be manufactured stably and efficiently,to provide an ink set that can be used in order to stably andefficiently manufacture a three-dimensional shaped article having amatte-toned texture, and to provide a three-dimensional shaped articlehaving a matte-toned texture.

Such aspects are achieved by the present invention described below.

A three-dimensional shaped article manufacturing method of the presentinvention is a method for manufacturing a three-dimensional shapedarticle by laminating layers formed by discharging and curing inksincluding a curable resin, the method comprising applying a substantivesection-forming ink to a region that forms the three-dimensional shapedarticle, and applying a sacrificial layer-forming ink for forming asacrificial layer to a region that is adjacent to a region that forms anoutermost layer of the three-dimensional shaped article and on a surfaceside of the outermost layer, a viscoelasticity of the sacrificiallayer-forming ink during curing of the substantive section-forming inkbeing less than a viscoelasticity of the substantive section-forming inkduring curing of the substantive section-forming ink.

This makes it possible to provide a three-dimensional shaped articlemanufacturing method by which a three-dimensional shaped article havinga matte-toned texture can be manufactured stably and efficiently.

The three-dimensional shaped article manufacturing method of the presentinvention, preferably, further comprises removing the sacrificial layerfrom a provisional molded article obtained by curing the substantivesection-forming ink and the sacrificial layer-forming ink.

This makes it possible for an observer to more suitably view a surfacestate that has a finely detailed wrinkling, because the substantivesection is exposed in the three-dimensional shaped article that isultimately obtained. For this reason, the effects of the presentinvention are more prominently exhibited.

In the three-dimensional shaped article manufacturing method of thepresent invention, preferably, the sacrificial layer-forming inkincludes one or more species selected from the group consisting oftetrahydrofurfuryl (meth)acrylate, ethoxyethoxy ethyl (meth)acrylate,polyethylene glycol di(meth)acrylate, and (meth)acryloylmorpholine.

This makes it possible to cure the sacrificial layer-forming ink at amore appropriate speed of curing, causes the matte-toned outerappearance to be more reliably obtained in the three-dimensional shapedarticle, and makes it possible to provide the three-dimensional shapedarticle with particularly excellent productivity.

In the three-dimensional shaped article manufacturing method of thepresent invention, preferably, the substantive section-forming inkincludes one or more species selected from the group consisting of2-(2-vinyloxyethoxy) ethyl (meth)acrylate, polyether-based aliphaticurethane (meth)acrylate oligomer,2-hydroxy-3-phenoxypropyl(meth)acrylate, and4-hydroxybutyl(meth)acrylate.

This makes it possible to cure the substantive section-forming ink at amore appropriate speed of curing, causes the matte-toned outerappearance to be more reliably obtained in the three-dimensional shapedarticle, and makes it possible to provide the three-dimensional shapedarticle with particularly excellent productivity.

In the three-dimensional shaped article manufacturing method of thepresent invention, preferably, the substantive section-forming ink andthe sacrificial layer-forming ink both include a polymerizationinitiator, a content ratio of the polymerization initiator in thesubstantive section-forming ink being higher than a content ratio of thepolymerization initiator in the sacrificial layer-forming ink.

This makes it possible to cure the substantive section-forming ink andthe sacrificial layer-forming ink each at a more suitable speed, andcauses the matte-toned outer appearance to be even more reliablyobtained in the three-dimensional shaped article.

Also, for example, adjusting the treatment conditions in the curing stepmakes it possible to give the sacrificial layer a comparatively lowerdegree of polymerization even while giving the substantive section anadequately high degree of curing after the end of the curing step. Thisresults in making it possible to eventually more easily remove thesacrificial layers in the sacrificial layer removal step and making itpossible to give the three-dimensional shaped article particularlyexcellent productivity.

In the three-dimensional shaped article manufacturing method of thepresent invention, preferably, the substantive section-forming ink andthe sacrificial layer-forming ink both includebis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide and/or2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide as a polymerizationinitiator.

This makes it possible to cure the substantive section-forming ink andthe sacrificial layer-forming ink at a more appropriate speed of curing,causes the glossy outer appearance to be more reliably obtained in thethree-dimensional shaped article, and makes it possible to provide thethree-dimensional shaped article with particularly excellentproductivity.

The substantive section that is formed by curing the substantivesection-forming ink can also be given particularly excellent mechanicalstrength and shape stability, and therefore the three-dimensional shapedarticle can be given particularly excellent strength, durability, andreliability.

In the three-dimensional shaped article manufacturing method of thepresent invention, preferably, a color ink containing a coloring agentand, in addition thereto, a colorless ink not containing a coloringagent are used as the substantive section-forming ink, the colorless inkbeing used upon formation of the region that forms the outermost layer,and the color ink being used upon formation of a region that is insidetherefrom.

This makes it possible to more suitably render the matte-toned texture.The substantive section that includes the coloring agent (in particular,pigment) is more brittle and prone to scratches, chipping, and the likethan the substantive section that does not include the coloring agent,but providing the region (coating layer) formed using the substantivesection-forming ink that does not include the coloring agent makes itpossible to effectively prevent the occurrence of such problems.

In the three-dimensional shaped article manufacturing method of thepresent invention, preferably, a chromatic color ink and a white ink areused as a color ink containing a coloring agent, the white ink beingused upon formation of a region inside of a region formed using thechromatic color ink.

This makes it possible for the region (a first region) to which thewhite ink is applied to exhibit masking, and makes it possible tofurther raise the chroma of the three-dimensional shaped article.

Also, the effect where the matte-toned texture is obtained due to thedifference in the viscoelasticity of the substantive section-forming inkand the sacrificial layer-forming ink and the effect where the chroma isincreased act synergistically together, making it possible to give thethree-dimensional shaped article a particularly excellent aestheticappearance (aesthetic).

In the three-dimensional shaped article manufacturing method of thepresent invention, preferably, a plurality of different types of thesacrificial layer-forming ink are used.

This makes it possible, for example, for the three-dimensional shapedarticle that is ultimately obtained to have a plurality of regions atwhich the degree of matte is different. As a result, it becomes possibleto render a more complex outer appearance, and the three-dimensionalshaped article can be given a particularly excellent aestheticappearance (aesthetics), luxuriousness, and the like.

In the three-dimensional shaped article manufacturing method of thepresent invention, preferably, the sacrificial layer-forming ink isselectively applied to a part of the region that is adjacent to theregion that forms the outermost layer of the three-dimensional shapedarticle and on the surface side of the outermost layer.

This causes the three-dimensional shaped article that is ultimatelyobtained to be one where a site that presents with a matte-toned textureand a site that presents with another kind of texture both exist, thusmaking it possible to render more complex outer appearances and makingit possible to give the three-dimensional shaped article a particularlyexcellent aesthetic appearance (aesthetics), luxuriousness, and thelike.

A three-dimensional shaped article manufacturing apparatus of thepresent invention is for manufacturing a three-dimensional shapedarticle by laminating layers formed by discharging and curing inksincluding a curable resin, the apparatus including: a first dischargeunit configured to discharge a substantive section-forming ink to aregion that forms the three-dimensional shaped article; a seconddischarge unit configured to discharge a sacrificial layer-forming inkfor forming a sacrificial layer to a region that is adjacent to a regionthat forms an outermost layer of the three-dimensional shaped articleand on a surface side of the outermost layer; and a curing unitconfigured to cure the substantive section-forming ink and thesacrificial layer-forming ink, a viscoelasticity of the sacrificiallayer-forming ink during curing of the substantive section-forming inkbeing less than a viscoelasticity of the substantive section-forming inkduring curing of the substantive section-forming ink.

This makes it possible to provide a three-dimensional shaped articlemanufacturing apparatus by which a three-dimensional shaped articlehaving a matte-toned texture can be manufactured stably and efficiently.

An ink set of the present invention is used for manufacturing athree-dimensional shaped article by laminating layers formed bydischarging and curing inks including a curable resin, the ink setincluding: a substantive section-forming ink applied to a region thatforms the three-dimensional shaped article, and a sacrificiallayer-forming ink applied to a region that is adjacent to a region thatforms an outermost layer of the three-dimensional shaped article and ona surface side of the outermost layer, a viscoelasticity of thesacrificial layer-forming ink during curing of the substantivesection-forming ink being less than a viscoelasticity of the substantivesection-forming ink during curing of the substantive section-formingink.

This makes it possible to provide an ink set by which athree-dimensional shaped article having a matte-toned texture can bemanufactured stably and efficiently.

A three-dimensional shaped article of the present invention ismanufactured using the three-dimensional shaped article manufacturingmethod of the present invention.

This makes it possible to provide a three-dimensional shaped articlehaving a matte-toned texture.

A three-dimensional shaped article of the present invention ismanufactured using the three-dimensional shaped article manufacturingapparatus of the present invention.

This makes it possible to provide a three-dimensional shaped articlehaving a matte-toned texture.

A three-dimensional shaped article of the present invention ismanufactured using the ink set of the present invention.

This makes it possible to provide a three-dimensional shaped articlehaving a matte-toned texture.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal

DISCLOSURE

FIGS. 1A to 1H are cross-sectional views schematically illustratingrespective steps as regards a preferred embodiment of a method ofmanufacturing a three-dimensional shaped article of the presentinvention;

FIG. 2 is a schematic cross-sectional view for describing anothersurface shape that can be formed in the present invention; and

FIG. 3 is a cross-sectional view schematically illustrating a preferredembodiment of an apparatus for manufacturing a three-dimensional shapedarticle of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Preferred embodiments of the present invention shall now be described ingreater detail below, with reference to the accompanying drawings.

<<Method of Manufacturing a Three-Dimensional Shaped Article>>

First, a method of manufacturing a three-dimensional shaped article inthe present invention shall be described.

FIGS. 1A to 1H are cross-sectional views schematically illustratingrespective steps as regards a preferred embodiment of a method ofmanufacturing a three-dimensional shaped article of the presentinvention, and FIG. 2 is a schematic cross-sectional view for describinganother surface shape that can be formed in the present invention.

As illustrated in FIGS. 1A to 1H, a method of manufacturing athree-dimensional shaped article 10 of the present embodiment comprises:ink discharge steps (FIGS. 1A, 1C, 1E) in which a substantivesection-forming ink (first ink) 11′ comprising a curable resin and asacrificial layer-forming ink (second ink) 12′ comprising a curableresin are discharged in a predetermined pattern by inkjet; curing steps(FIGS. 1B, 1D, 1F) in which a layer 1 including a substantive section 11and a sacrificial layer 12 is formed by curing the dischargedsubstantive section-forming ink 11′ and sacrificial layer-forming ink12′; these steps being sequentially repeated to obtain a provisionalmolded article 10′ (FIG. 1G), and thereafter a sacrificial layer removalstep (FIG. 1H) in which the sacrificial layers 12 are removed.

In the ink discharge steps, the substantive section-forming ink 11′ isapplied to a region that is to become the substantive section 11 of thethree-dimensional shaped article 10, and the sacrificial layer-formingink 12′ is applied to a region which is adjacent to a region that is tobecome an outermost layer of the substantive section 11 of thethree-dimensional shaped article 10 and which is on the surface side ofthe outermost layer.

The viscoelasticity of the sacrificial layer-forming ink 12′ duringcuring of the substantive section-forming ink 11′ is less than theviscoelasticity of the substantive section-forming ink 11′ during curingof the substantive section-forming ink 11′. “During curing” refers to asemi-cured state at a point in time where the fluidity is lost when thesubstantive section-forming ink 11′ is being cured.

Satisfying such conditions causes a fine wrinkling to occur at a sitethat is to become an outer surface of the substantive section 11 whenthe substantive section-forming ink 11′ is being cured, and causes thethree-dimensional shaped article 10 that is ultimately obtained to havea matte-toned outer appearance. Satisfying the aforementioned conditionsalso makes it possible to stably and efficiently manufacture thethree-dimensional shaped article 10.

In the present invention, it is possible to employ a value obtained bymeasurement using a variety of viscoelasticity measurement instruments(for example, ARES by Rheometric Scientific, or the like) as theviscoelasticity, but it would also be possible to determine therelationship between the viscoelasticities of the two inks withoutactually measuring the viscosity during curing of the substantivesection-forming ink, from, for example, the relationship between theinitial viscosities (the viscosities in the state prior to when thecuring reaction is allowed to proceed) of the substantivesection-forming ink and the sacrificial layer-forming ink, therelationship between the degrees of curing of the two inks after thesubstantive section-forming ink and the sacrificial layer-forming inkhave been subjected to the curing treatment under the same conditions,or the like.

Each of the steps shall now be described below.

<<Ink Discharge Steps (Ink Application Steps)>>

In the ink discharge steps, the substantive section-forming ink 11′comprising a curable resin and the sacrificial layer-forming ink 12′comprising a curable resin are discharged in a predetermined pattern byinkjet (FIGS. 1A, 1C, 1E).

More specifically, the substantive section-forming ink 11′ is applied toa region that is to become the substantive section 11 of thethree-dimensional shaped article 10, and the sacrificial layer-formingink 12′ is applied to a region which is adjacent to a region that is tobecome an outermost layer of the substantive section 11 of thethree-dimensional shaped article 10 and which is on the surface side ofthe outermost layer.

In the first of the ink discharge steps, the inks (the substantivesection-forming ink 11′ and the sacrificial layer-forming ink 12′) aredischarged onto a stage 3 (FIG. 1A), and in the second and subsequentink discharge steps, the inks (the substantive section-forming ink 11′and the sacrificial layer-forming ink 12′) are discharged onto a layer 1(FIGS. 1C, 1E).

In this manner, in the present embodiment, not only is ink (thesubstantive section-forming ink 11′) applied to the site that is tobecome the substantive section 11 of the three-dimensional shapedarticle 10, but also ink (the sacrificial layer-forming ink 12′) isapplied to the surface side thereof, as well.

So doing adjusts the surface shape of the three-dimensional shapedarticle 10 and in particular produces a surface shape that has a finewrinkling and presents with a matte-toned outer appearance.

Applying the sacrificial layer-forming ink 12′ and forming thesacrificial layer 12 makes it possible for the substantivesection-forming ink 11′ for forming an upper layer (second layer) to besuitably supported by the sacrificial layer of a lower layer (firstlayer), even for where a layer (second layer) constituting thethree-dimensional shaped article 10 has a portion bulging out from anouter peripheral section of the layer (first layer) therebelow (forexample, the relationship between the first layer and second layer fromthe bottom, the relationship between the second layer and third layerfrom the bottom, and the relationship between the fourth layer and fifthlayer from the bottom in the drawings). Therefore, unintendeddeformation (in particular, sagging and the like) of the substantivesection 11 can be suitably prevented (the sacrificial layer 12 of thefirst layer functions as a support material), and the three-dimensionalshaped article 10 that is ultimately obtained can be given particularlyexcellent dimensional accuracy.

In the present steps, the inks (the substantive section-forming ink 11′and the sacrificial layer-forming ink 12′) are applied by inkjet, andtherefore the inks can be applied with favorable reproducibility evenwhen the pattern of application of the inks (the substantivesection-forming ink 11′ and the sacrificial layer-forming ink 12′) has afinely-detailed shape. As a result, the three-dimensional shaped article10 that is ultimately obtained can be given particularly highdimensional accuracy, and also the surface shape and appearance of thethree-dimensional shaped article 10 can be more suitably controlled.

The substantive section-forming ink 11′ and the sacrificiallayer-forming ink 12′ shall be described in greater detail below.

Though the amount of ink applied in the present steps is notparticularly limited, the thickness of the first layer formed in thesubsequent curing step is preferably 30 to 500 μm, more preferably 70 to150 μm.

This makes it possible to more effectively prevent, inter alia, theoccurrence of unintended irregularities in the three-dimensional shapedarticle 10 that is manufactured, while also giving the three-dimensionalshaped article 10 ample and excellent productivity, and makes itpossible to give the three-dimensional shaped article 10 particularlyexcellent dimensional accuracy. The surface state and appearance of thethree-dimensional shaped article 10 that is ultimately obtained can alsobe more suitably controlled.

<<Curing Steps (Layer Formation Steps)>>

After the inks (the substantive section-forming ink 11′ and thesacrificial layer-forming ink 12′) have been applied (discharged) in theink discharge steps, the curing components (curable resins) included inthe inks (the substantive section-forming ink 11′ and the sacrificiallayer-forming ink 12′) are cured (FIGS. 1B, 1D, 1F). This produces thelayer 1 having the substantive section 11 and the sacrificial layer 12.

The viscoelasticity of the substantive section-forming ink 11′ and theviscoelasticity of the sacrificial layer-forming ink 12′ when thesubstantive section-forming ink 11′ and the sacrificial layer-formingink 12′ are being cured in the present steps (the instant where thesubstantive section-forming ink 11′ is cured) satisfy a predeterminedrelationship. Namely, the viscoelasticity of the sacrificiallayer-forming ink 12′ when the substantive section-forming ink 11′ andthe sacrificial layer-forming ink 12′ are being cured in the presentsteps is lower than the viscoelasticity of the substantivesection-forming ink 11′.

This makes it possible for the sacrificial layer-forming ink 12′ to movemicroscopically during curing, and makes it possible to produce a finewrinkling in the surface (site where the substantive section-forming ink11′ has been in contact with the sacrificial layer-forming ink 12′) ofthe substantive section 11 due to the stress during curing. As a result,the three-dimensional shaped article 10 that is ultimately obtained hasa fine wrinkling on the surface and presents with a matte-toned outerappearance.

Also, adjusting the duration from landing of the inks until completionof curing (for example, the intensity of irradiation with energy rays,or the like) makes it possible to easily and reliably control the extentof matte toning. As a result, the three-dimensional shaped article 10that is ultimately obtained can be reliably given a desired appearance.

Also, curing the curing components (curable resins) included in the inksin the present steps causes the three-dimensional shaped article 10 thatis ultimately obtained to be constituted of a cured article, andtherefore to have more excellent mechanical strength, durability, andthe like than a three-dimensional shaped article constituted of, forexample, a thermoplastic resin or the like.

The present steps vary depending on the types of curing components(curable resins), but, for example, in a case where the curingcomponents (curable resins) are heat-curable resins, the present stepscan be carried out by heating; in a case where the curing components(curable resins) are photocurable resins, the present steps can becarried out by irradiating with a corresponding light (for example, thepresent steps can be carried out by irradiating with ultraviolet rays ina case where the curing components (curable resins) areultraviolet-curable resins).

The description above posits applying the inks in a shape and patterncorresponding to the layer 1 and thereafter curing the entirety of thelayer (layer corresponding to layer 1) constituted of the inks, but inthe present invention, the discharging of ink and the curing of ink mayalso proceed simultaneously for at least a partial region. That is tosay, prior to when the entirety of the pattern of the entirety of onelayer 1 is formed, the curing reaction may be allowed to proceedsequentially from a site to which the inks were applied as regards atleast a part of the region corresponding to the layer 1. As regards atleast a portion of contact between the substantive section-forming ink11′ and the sacrificial layer-forming ink 12′ (a portion at which thesubstantive section 11 and the sacrificial layer 12 are to be incontact), however, the curing treatment (for example, curing withultraviolet rays, in a case where the curing components included in thetwo inks are ultraviolet-curable resins) would be carried out at thesame time, and the curing treatment for the substantive section-formingink 11′ and the curing treatment for the sacrificial layer-forming ink12′ would not be performed separately.

Also, in the present steps, there is no need to completely cure thecuring components included in the inks. For example, at the end of thepresent steps, the sacrificial layer-forming ink 12′ may have achievedan incompletely cured state, the substantive section-forming ink 11′having been cured at a higher degree of cure than the sacrificiallayer-forming ink 12′.

This makes it possible to easily perform the sacrificial layer removalstep described below, and makes it possible to further improve theproductivity of the three-dimensional shaped article 10.

At the end of the present steps, also, a state where the substantivesection-forming ink 11′ has been cured in an incomplete state may alsobe achieved. In such a case, too, the three-dimensional shaped article10 that is ultimately obtained can be given excellent mechanicalstrength and the like by, for example, carrying out a true curing stepfor raising the degree of cure with respect to the substantivesection-forming ink 11′ (the substantive section 11) that is in theincomplete curing state after having carried out a later step (forexample, the “ink discharge step” that follows formation of theunderlying layer 1 in the curing steps, or the like). Also, applying theink for forming an upper layer in the state where the substantivesection-forming ink 11′ (lower layer) has been cured in the incompletestate makes it possible to impart particularly excellent adhesionbetween the layers.

The aforementioned sequence of steps is repeatedly carried out. Thisachieves a state where the layers 1 adjacent to one another are bondedtogether, and produces a laminate in which a plurality of the layers 1in such a state have been laminated, i.e., the provisional moldedarticle 10′ in which the sacrificial layers 12 are provided to thesurfaces of the substantive sections 11 (see FIG. 1G).

<<Sacrificial Layer Removal Step>>

After the aforementioned sequence of steps has been repeatedly carriedout, the sacrificial layers 12 are removed (FIG. 1H).

This produces a three-dimensional shaped article 10 with which thesubstantive section 11, to the surface of which a fine wrinkling hasbeen provided, is exposed. Such a three-dimensional shaped article 10possesses a matte-toned texture.

Examples of methods of removing the sacrificial layers 12 could includea method with which a liquid that selectively dissolves the sacrificiallayers 12 is used to selectively dissolve and remove the sacrificiallayers 12; or a method with which a liquid that has higher absorption bythe sacrificial layers 12 than the substantive section 11 is used tocause the liquid to be selectively absorbed into the sacrificial layers12, thereby expanding the sacrificial layers 12, or lowering themechanical strength of the sacrificial layers 12 whereupon thesacrificial layers 12 are peeled off or destroyed.

The liquid used in the present step would vary depending on theconstituent materials of the substantive section 11 and the sacrificiallayers 12, and the like, but examples that could be used include: water;methanol, ethanol, isopropyl alcohol, n-propyl alcohol, butanol,isobutanol, and other alcohols; or glycerin, ethylene glycol, diethyleneglycol, triethylene glycol, propylene glycol, dipropylene glycol, andother glycols. The liquid may comprise one or more species selected fromthese, and may also have: a water-soluble substance that produceshydroxide ions of sodium hydroxide, potassium hydroxide, sodium hydrogencarbonate, or organic amines in order to improve the dissolubility ofthe sacrificial layers; a surfactant that facilitates separation of thesacrificial layers that have been peeled off; or the like that is mixedtherein.

Though not particularly limited, examples of the method of applying theaforementioned liquid to the provisional molded article 10′ couldinclude employing a variety of methods such as immersion, spraying, orcoating.

The description above posits that a liquid is used, but a substance (forexample, a solid, gas, supercritical fluid, or the like) that has asimilar function may also be used.

Ultrasonic vibrations may also be applied when the liquid is beingapplied or after the liquid has been applied.

This makes it possible to facilitate the removal of the sacrificiallayers 12 and makes it possible to give the three-dimensional shapedarticle 10 particularly excellent productivity.

In the present invention, the surface state (surface state that has afine wrinkling) of the substantive section 11 of the three-dimensionalshaped article 10 can be viewed in the state of the provisional moldedarticle 10; in a case where a matte-toned outer appearance is presented,the sacrificial layers 12 need not be removed, but removing thesacrificial layers 12 as in the present embodiment makes it possible forthe surface state that has fine wrinkling to be suitably viewed by anobserver, because the substantive section 11 is exposed. For thisreason, the effects of the present invention are more prominentlyexhibited.

In the configuration illustrated in FIGS. 1A to 1H, the matte tone isrendered due to the differences in viscosity between the substantivesection-forming ink 11′ and the sacrificial layer-forming ink 12′, butin the configuration illustrated in FIG. 2, in addition thereto, thesurface area of the layers 1 is adjusted so that stepped differences(concavities and convexities) are present in repetition between each ofthe layers 1 in the three-dimensional shaped article 10 in the form of alaminate, while the general shape of the three-dimensional shapedarticle 10 as a whole is upheld.

This causes the fine wrinkling produced by the differences in viscositybetween the substantive section-forming ink 11′ and the sacrificiallayer-forming ink 12′ and the stepped differences (concavities andconvexities) that are present between each of the layers 1 tosynergistically affect each other in the outer appearance of thethree-dimensional shaped article 10, thus making it possible to obtainan outer appearance that has conventionally been impossible to render.

The description above posits that the sacrificial layer-forming ink 12′is applied so as to be in contact with the substantive section-formingink 11′ in the entire region that is to become the outermost layer ofthe three-dimensional shaped article 10, but the sacrificiallayer-forming ink 12′ may instead be applied so as to be in contact withthe substantive section-forming ink 11′ only in a part of the regionthat is to become the outermost layer of the three-dimensional shapedarticle 10.

This causes the three-dimensional shaped article 10 that is ultimatelyobtained to be one where a site that presents with a matte-toned textureand a site that presents with another kind of texture both exist, thusmaking it possible to render more complex outer appearances and makingit possible to give the three-dimensional shaped article 10 aparticularly excellent aesthetic appearance (aesthetics), luxuriousness,and the like.

According to the method of manufacture of the present invention asdescribed above, a three-dimensional shaped article that has amatte-toned texture can be manufactured stably and efficiently. Also,the yield of the three-dimensional shaped article is improved andtherefore the present invention is also advantageous in terms ofreducing the costs of manufacturing the three-dimensional shapedarticle.

<<Apparatus for Manufacturing a Three-Dimensional Shaped Article>>

First, the apparatus for manufacturing a three-dimensional shapedarticle of the present invention shall be described.

FIG. 3 is a cross-sectional view schematically illustrating a preferredembodiment of an apparatus for manufacturing a three-dimensional shapedarticle of the present invention.

An apparatus 100 for manufacturing a three-dimensional shaped article isone that manufactures the three-dimensional shaped article 10 by usingthe substantive section-forming ink 11′ and the sacrificiallayer-forming ink 12′ to repeatedly mold and laminate the layers 1.

As illustrated in FIG. 3, the apparatus 100 for manufacturing athree-dimensional shaped article has: a control unit 2; the stage 3; afirst ink discharge unit (substantive section-forming ink applyingmeans) 4 for discharging the substantive section-forming ink 11′; asecond ink discharge unit (sacrificial layer-forming ink applying means)5 for discharging the sacrificial layer-forming ink 12′, and an energyray irradiating means (curing means) 6 for irradiating with energy raysfor curing the substantive section-forming ink 11′ and the sacrificiallayer-forming ink 12′.

The control unit 2 has a computer 21 and a drive control unit 22.

The computer 21 is, inter alia, a common desktop computer configured tobe provided with a CPU, memory, and the like inside. The computer 21converts the shape of the three-dimensional shaped article 10 into datain the form of the model data, which is then sliced into many parallellayers of thin cross-sections to obtain cross-sectional data (slicedata) that is then outputted to the drive control unit 22.

The drive control unit 22 functions as a controlling means forrespectively driving the first ink discharge unit (substantivesection-forming ink applying means) 4, the second discharge unit(sacrificial layer-forming ink applying means) 5, the energy rayirradiating means (curing means) 6, and the like. A more specificexample of what is controlled is the discharged pattern and dischargedamount of the substantive section-forming ink 11′ from the first inkdischarge unit (substantive section-forming ink applying means) 4, thedischarged pattern and discharged amount of the sacrificiallayer-forming ink 12′ from the second discharge unit (sacrificiallayer-forming ink applying means) 5, the irradiated amount andirradiation timing of the energy rays from the energy ray irradiatingmeans (curing means) 6, and the like.

The stage 3 is a region where the substantive section-forming ink 11′and the sacrificial layer-forming ink 12′ are applied.

The stage 3 is one that has a flat surface (the site where thesubstantive section-forming ink 11′ and the sacrificial layer-formingink 12′ are applied).

This makes it possible to easily and reliably form layers 1 that have ahighly uniform thickness. It is also possible to effectively preventunintended deformation or the like from taking place in thethree-dimensional shaped article 10 that is manufactured.

The stage 3 is preferably constituted of a high-strength material.Examples of the constituent material of the stage 3 include a variety ofmetal materials such as stainless steel.

The surface (site where the substantive section-forming ink 11′ and thesacrificial layer-forming ink 12′ are applied) of the stage 3 may alsobe subjected to a surface treatment.

This makes it possible, for example, to more effectively prevent theconstituent material of the substantive section-forming ink 11′ and theconstituent material of the sacrificial layer-forming ink 12′ fromadhering to the stage 3, to give the stage 3 excellent durability, toachieve production of the three-dimensional shaped article 10 that haslong-term stability, and so forth. Examples of the material used for thesurface treatment of the surface of the stage 3 could include a fluorineresin such as polytetrafluoroethylene, or the like.

The first ink discharge unit (substantive section-forming ink applyingmeans) 4 is one that discharges the substantive section-forming ink 11′by inkjet.

Providing such a first ink discharge unit (substantive section-formingink applying means) 4 makes it possible to apply a desired amount of thesubstantive section-forming ink 11′ to a desired site with afinely-detailed pattern, and makes it possible to manufacture even thethree-dimensional shaped article 10, which has a finely-detailedstructure, at particularly favorable productivity.

For the liquid droplet discharge format (inkjet format), it would bepossible to use a piezoelectric format, a format for discharging the inkusing bubbles generated by heating the ink, or the like, but apiezoelectric format is preferable in terms of the difficulty ofaltering the constituent components of the ink and the like.

With the first ink discharge unit (substantive section-forming inkapplying means) 4, a command coming from the drive control unit 22controls the pattern that is to be formed, the amount of substantivesection-forming ink 11′ applied, and the like. The discharged pattern,discharged amount, and the like of the substantive section-forming ink11′ from the first ink discharge unit (substantive section-forming inkapplying means) 4 are determined on the basis of the slice data.

This makes it possible to apply a necessary and sufficient amount of thesubstantive section-forming ink 11′ to a target site, makes it possibleto reliably form the substantive section 11 of the desired pattern, andmakes it possible to give the three-dimensional shaped article 10 morereliably excellent dimensional accuracy and mechanical strength. Also,in a case where the substantive section-forming ink 11′ is one thatcomprises a coloring agent, then the desired color tone, patterning, andthe like can be obtained.

The first ink discharge unit (substantive section-forming ink applyingmeans) 4 has the ability to move in the X-direction and the Y-directionrelative to the stage, and also has the ability to move in theZ-direction.

This makes it possible to uphold the desired value of distance between anozzle surface (discharge unit distal end) of the first ink dischargeunit (substantive section-forming ink applying means) 4 and a section oflanding of the substantive section-forming ink 11′ even in a case wherethe layers 1 have been laminated.

The second ink discharge unit (sacrificial layer-forming ink applyingmeans) 5 is one that discharges the sacrificial layer-forming ink 12′ byinkjet.

Providing such a second ink discharge unit (sacrificial layer-formingink forming ink applying means) 5 makes it possible to apply a desiredamount of the sacrificial layer-forming ink 12′ to a desired site with afinely-detailed pattern, and makes it possible, even when thethree-dimensional shaped article 10 that is to be manufactured has afinely-detailed structure, to form sacrificial layers 12 of the desiredsize and shape at the desired shapes, thus making it possible to morereliably form the surface shape and outer appearance of thethree-dimensional shaped article 10. It is also possible to give thethree-dimensional shaped article 10 particularly excellent productivity.

The format of ink droplet discharge (inkjet format), control, driving,and the like as regards the second ink discharge unit (sacrificiallayer-forming ink applying means) 5 are similar to those described abovefor the first ink discharge unit (substantive section-forming inkapplying means) 4.

The energy ray irradiating means (curing means) 6 is one that irradiateswith energy rays for curing the substantive section-forming ink 11′ andthe sacrificial layer-forming ink 12′.

Providing the curing means 6 of such description makes it possible togive the three-dimensional shaped article 10 that is ultimately obtainedexcellent mechanical strength and also makes it possible to reliablycontrol the surface shape and outer appearance of the three-dimensionalshaped article 10.

The energy ray irradiating means (curing means) 6 is one that has anirradiation surface area that allows for the substantive section-formingink 11′ and the sacrificial layer-forming ink 12′ to be irradiated withthe energy rays at the same time, as regards at least the portion ofcontact between the substantive section-forming ink 11′ and thesacrificial layer-forming ink 12′ (the portion at which the substantivesection 11 and the sacrificial layer 12 are to be in contact with oneanother).

The type of energy rays with which the energy ray irradiating means(curing means) 6 irradiates will vary depending on the constituentmaterials of the substantive section-forming ink 11′ and the sacrificiallayer-forming ink 12′, but examples include ultraviolet rays, visiblelight rays, infrared rays, X-rays, gamma rays, an electron beam, an ionbeam, or the like. In particular, it would be preferable to useultraviolet rays in terms of costs and the productivity of thethree-dimensional shaped article.

Though not illustrated in the drawings, the apparatus 100 formanufacturing a three-dimensional shaped article may be one that isprovided with a sacrificial layer removing means for removing thesacrificial layers 12, and a drying means for drying thethree-dimensional shaped article 10 from which the sacrificial layershave been removed.

Examples of a sacrificial layer removing means include one thatmechanically destroys and removes the sacrificial layers 12, a tankwhich holds the liquid as described above and in which the provisionalmolded article 10′ is immersed, a liquid spraying means for spraying theliquid as described above toward the provisional molded article 10′, aliquid coating means for coating the provisional molded article 10′ withthe liquid as described above, and so forth.

Examples of a drying means include one that supplies a heated gas ordried gas, as described above, or a pressure-reducing means that reducesthe pressure of a space in which the three-dimensional shaped article 10is held.

The apparatus for manufacturing a three-dimensional shaped article ofthe present invention need only perform at least a part of the stepsdescribed above, and a part of the steps described above may beperformed without using the apparatus for manufacturing athree-dimensional shaped article.

According to the apparatus for manufacturing a three-dimensional shapedarticle of the present invention described above, a three-dimensionalshaped article that has a matte-toned texture can be manufactured stablyand efficiently. Also, the yield of the three-dimensional shaped articleis improved and therefore the present invention is also advantageous interms of reducing the costs of manufacturing the three-dimensionalshaped article.

<<Ink Set>>

Next, the ink set of the present invention shall be described.

The ink set of the present invention comprises at least one kind ofsubstantive section-forming ink 11′ and at least one kind of sacrificiallayer-forming ink 12′. The ink set of the present invention is one thatis applied to the method of manufacturing a three-dimensional shapedarticle and apparatus for manufacturing a three-dimensional shapedarticle in the present invention as described above.

<Substantive Section-Forming Ink>

The substantive section-forming ink 11′ comprises at least a curableresin (curing component).

(Curable Resin)

Examples of the curable resin (curing component) include: a heat-curableresin; a variety of photocurable resins, such as a visible light-curableresin (a photocurable resin in the narrow sense) that is cured by lightin the visible light range, an ultraviolet ray-curable resin, or aninfrared ray-curable resin; an X-ray curable resin; and the like, fromwhich one kind can be selected for use, or two or more kinds can becombined for use.

It is particularly preferable to use an ultraviolet ray-curable resin(polymerizable compound) in terms of the mechanical strength of theresulting three-dimensional shaped article 10, the productivity of thethree-dimensional shaped article 10, the storage stability of thesubstantive section-forming ink 11′, and so forth.

Preferably used as an ultraviolet ray-curable resin (polymerizablecompound) is one with which an addition polymerization or ring-openingpolymerization is initiated by radical species or cation species or thelike produced from a photopolymerization initiator by irradiation withultraviolet rays, thus creating a polymer. Manners of polymerization inaddition polymerization include radical, cationic, anionic, metathesis,and coordination polymerization. Manners of polymerization inring-opening polymerization include cationic, anionic, radical,metathesis, and coordination polymerization.

Examples of addition polymerizable compounds include compounds that haveat least one ethylenically unsaturated double bond. Compounds that haveat least one, preferably two terminal ethylenically unsaturated bondscan be preferably used as an addition polymerizable compound.

Ethylenically unsaturated polymerizable compounds have the chemical formof monofunctional polymerizable compounds and polyfunctionalpolymerizable compounds, or mixtures thereof.

Examples of monofunctional polymerizable compounds include unsaturatedcarboxylic acids (for example, acrylic acid, methacrylic acid, itaconicacid, crotonic acid, isocrotonic acid, maleic acid, and the like) oresters or amides thereof.

Polyfunctional polymerizable compounds includes esters of unsaturatedcarboxylic acids and aliphatic polyhydric alcohol compounds, and amidesof unsaturated carboxylic acids and aliphatic amine compounds.

It would also be possible to use: a product of an addition reactionbetween an isocyanate or an epoxy and an unsaturated carboxylic acidester or amide that has a nucleophilic substituent such as a hydroxylgroup, an amino group, or a mercapto group; a product of a dehydrationcondensation reaction with a carboxylic acid; or the like. It would alsobe possible to use: the product of an addition reaction between anunsaturated carboxylic acid ester or amide having an electrophilicsubstituent group such as an isocyanate group or an epoxy group and analcohol, amine, or thiol; or the product of a substitution reactionbetween an unsaturated carboxylic acid ester or amide having a leavinggroup substituent such as a halogen group or a tosyloxy group and analcohol, amine, or thiol.

A (meth)acrylic acid ester is representative as a specific example of aradical polymerizable compound that is the ester of an unsaturatedcarboxylic acid and an aliphatic polyhydric alcohol compound; either amonofunctional one or a polyfunctional one could be used.

Specific examples of a monofunctional (meth)acrylate include:tolyloxyethyl (meth)acrylate, phenyloxyethyl (meth)acrylate, cyclohexyl(meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, isobornyl(meth)acrylate, dipropylene glycol di(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, ethoxyethoxy ethyl(meth)acrylate, 2-(2-vinyloxyethoxy)ethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate,4-hydroxybutyl (meth)acrylate, and the like.

Specific examples of bifunctional (meth)acrylates include ethyleneglycol di(meth)acrylate, triethylene glycol di(meth)acrylate,1,3-butanediol di(meth)acrylate, tetramethylene glycol di(meth)acrylate,propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate,hexanediol di(meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate,tetraethylene glycol di(meth)acrylate, pentaerythritol di(meth)acrylate,and dipentaerythritol di(meth)acrylate.

Specific examples of trifunctional (meth)acrylates include trimethylolpropane tri(meth)acrylate, trimethylol ethane tri(meth)acrylate,trimethylolpropane alkylene oxide-modified tri(meth)acrylate,pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate,trimethylol propane tri((meth)acryloyloxypropyl) ether, isocyanuric acidalkylene oxide-modified tri(meth)acrylate, propionic aciddipentaerythritol tri(meth)acrylate, tri((meth)acryloyloxyethyl)isocyanurate, hydroxypivalaldehyde-modified dimethylol propanetri(meth)acrylate, and sorbitol tri(meth)acrylate.

Specific examples of tetrafunctional (meth)acrylates includepentaerythritol tetra(meth)acrylate, sorbitol tetra(meth)acrylate,ditrimethylol propane tetra(meth)acrylate, propionic aciddipentaerythritol tetra(meth)acrylate, and ethoxylated pentaerythritoltetra(meth)acrylate.

Specific examples of pentafunctional (meth)acrylates) include sorbitolpenta(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Specificexamples of hexafunctional (meth)acrylates include dipentaerythritolhexa(meth)acrylate, sorbitol hexa(meth)acrylate, phosphazene alkyleneoxide-modified hexa(meth)acrylate, and captolactone-modifieddipentaerythritol hexa(meth)acrylate.

Examples of polymerizable compounds other than (meth)acrylates includeitaconic acid esters, crotonic acid esters, isocrotonic acid esters, andmaleic acid esters.

Examples of itaconic acid esters include ethylene glycol diitaconate,propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanedioldiitaconate, tetramethylene glycol diitaconate, pentaerythritoldiitaconate, and sorbitol tetraitaconate.

Examples of crotonic acid esters include ethylene glycol dicrotonate,tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, andsorbitol tetradicrotonate.

Examples of isocrotonic acid esters include ethylene glycoldiisocrotonate, pentaerythritol diisocrotonate, and sorbitoltetraisocrotonate.

Examples of maleic acid esters include ethylene glycol dimaleate,triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitoltetramaleate.

Examples of other esters that can be used also include: the aliphaticalcohol esters disclosed in Japanese Examined Patent Publication No.S46-27926, Japanese Examined Patent Publication No. S51-47334, andJapanese Unexamined Patent Publication No. S57-196231; those having anaromatic backbone disclosed in Japanese Unexamined Patent PublicationNo. 559-5240, Japanese Unexamined Patent Publication No. S59-5241, andJapanese Unexamined Patent Publication No. H2-226149; and the onecontaining an amino group disclosed in Japanese Unexamined PatentPublication No. HI-165613.

Specific examples of monomers of an amide of an unsaturated carboxylicacid and an aliphatic amine compound include methylene bis-acrylamide,methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide,1,6-hexamethylene bis-methacrylamide, diethylenetriamine trisacrylamide,xylylene bisacrylamide xylylene bismethacrylamide, and(meth)acryloylmorpholine.

Another example of a preferable amide monomer would be the one having acyclohexylene structure disclosed in Japanese Examined PatentPublication No. 554-21726.

Urethane-based addition polymerizable compounds manufactured using anaddition reaction between an isocyanate and a hydroxyl group are alsofavorable, and a specific example thereof could be a vinyl urethanecompound containing two or more polymerizable vinyl groups in a moleculeobtained by adding a vinyl monomer containing a hydroxyl grouprepresented in formula (1) below to a polyisocyanate compound having twoor more isocyanate groups in one molecule, as is disclosed in JapaneseExamined Patent Publication No. S48-41708.

CH₂═C(R¹)COOCH₂CH(R²)OH  (1)

(where R¹ and R² in the formula (1) each independently indicate an H orCH₃)

In the present invention, a cationic ring-opening polymerizable compoundhaving one or more cyclic ether groups such as an epoxy group or anoxetane group in the molecule can be favorably used as an ultravioletray-curable resin (polymerizable resin).

Examples of cationic polymerizable compounds include curable compoundscomprising a ring-opening polymerizable group, among which heterocyclicgroup-containing curable compounds are particularly preferable. Examplesof such curable compounds include an epoxy derivative, an oxetanederivative, a tetrahydrofuran derivative, a cyclic lactone derivative, acyclic carbonate derivative, an oxazoline derivative, or other suchcyclic imino ethers, or vinyl ethers; of these, epoxy derivatives,oxetane derivatives, and vinyl ethers are preferable.

Examples of preferable epoxy derivatives include monofunctional glycidylethers, polyfunctional glycidyl ethers, monofunctional alicyclicepoxies, and polyfunctional alicyclic epoxies.

Specific compounds for glycidyl ethers can be illustratively exemplifiedby diglycidyl ethers, (for example, ethylene glycol diglycidyl ether,bisphenol A diglycidyl ether, and the like), trifunctional or higherglycidyl ethers (for example, trimethylol ethane triglycidyl ether,trimethylol propane triglycidyl ether, glycerol triglycidyl ether,triglycidyl trishydroxyethyl isocyanurate, or the like), tetrafunctionalor higher glycidyl ethers (for example, sorbitol tetraglycidyl ether,pentaerythritol tetraglycyl ether, cresol novolac resin polyglycidylether, phenolnovolac resin polyglycidyl ether, and the like), alicyclicepoxies (for example, Celloxide 2021P, Celloxide 2081, Epolead GT-301,and Epolead GT-401 (Daicel Chemical Industries)), EHPE (Daicel ChemicalIndustries), phenol novolac resin polycyclohexyl epoxy methyl ether orthe like), and oxetanes (for example, OX-SQ, PNOX-1009 (Toagosei), andthe like).

As a polymerizable compound, an alicyclic epoxy derivative could bepreferably used. An “alicyclic epoxy group” is a term for a moietyobtained when a double bond of a cycloalkene group such as acyclopentene group or cyclohexene group is epoxidized with a suitableoxidizing agent such as hydrogen peroxide or a peroxy acid.

Preferable alicyclic epoxy compounds include polyfunctional alicyclicepoxies having two or more cyclohexene oxide groups or cyclopenteneoxide groups in one molecule. Specific examples of alicyclic epoxycompounds include 4-vinylcyclohexene dioxide,(3,4-epoxycyclohexyl)methyl-3,4-epoxycyclohexyl carboxylate,di(3,4-epoxycyclohexyl) adipate, di(3,4-epoxycyclohexylmethyl) adipate,bis(2,3-epoxycyclopentyl) ether, di(2,3-epoxy-6-methylcyclohexylmethyl)adipate, and dicyclopentadiene dioxide.

A glycidyl compound having a normal epoxy group without an alicyclicstructure in the molecule could be used either independently or incombination with an aforementioned alicyclic epoxy compound.

Examples of such normal glycidyl compounds could include glycidyl ethercompounds and glycidyl ester compounds, but it is preferable to use aglycidyl ether compound in combination.

Specific examples of glycidyl ether compounds include: an aromaticglycidyl ether compound such as 1,3-bis(2,3-epoxypropyloxy)benzene, abisphenol A epoxy resin, a bisphenol F epoxy resin, a phenol novolacepoxy resin, a cresol novolac epoxy resin, and a trisphenol methaneepoxy resin; and an aliphatic glycidyl ether compound such as1,4-butanediol glycidyl ether, glycerol triglycidyl ether, propyleneglycol diglycidyl ether, and trimethylol propane tritriglycidyl ether.Examples of a glycidyl ester could include a glycidyl ester of linoleicacid dimers.

As a polymerizable compound, it would be possible to use a compound thathas an oxetanyl group, which is a four-membered cyclic ether (thiscompound also being called simply an “oxetane compound” below). Anoxetanyl group-containing compound is a compound that has one or moreoxetanyl groups in one molecule.

Of the aforementioned curing components, the substantive section-formingink 11′ is particularly preferably one that comprises one or morespecies selected from the group consisting of 2-(2-vinyloxyethoxy) ethyl(meth)acrylate, a polyether-based aliphatic urethane (meth)acrylateoligomer, 2-hydroxy-3-phenoxypropyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate.

This makes it possible to cure the substantive section-forming ink 11′at a more appropriate speed of curing, causes the matte-toned outerappearance to be more reliably obtained in the three-dimensional shapedarticle 10, and makes it possible to provide the three-dimensionalshaped article 10 with particularly excellent productivity.

The substantive section 11 that is formed by curing the substantivesection-forming ink 11′ can also be given particularly excellentmechanical strength and shape stability. As a result, thethree-dimensional shaped article 10 can be given particularly excellentstrength, durability, and reliability.

Comprising these curing components also makes it possible to give thecured product of the substantive section-forming ink 11′ particularlylow swellability and solubility with respect to a variety of solvents(for example, water and the like). As a result, the sacrificial layers12 can be removed more reliably and at higher selectivity in thesacrificial layer removal step, and unintended deformation due to adefect being produced in the substantive section 11 or the like can beprevented. This results in the ability to more reliably give thethree-dimensional shaped article 10 higher dimensional accuracy.

Also, because the cured product of the substantive section-forming ink11′ can be given lower swellability (solvent absorption), it ispossible, for example, to omit or simplify a drying treatment serving aspost-treatment after the sacrificial layer removal step. Because thesolvent resistance of the three-dimensional shaped article 10 that isultimately obtained is also improved, the three-dimensional shapedarticle 10 is given particularly high reliability.

In particular, when the substantive section-forming ink 11′ comprises2-(2-vinyloxyethoxy) ethyl (meth)acrylate, the substantivesection-forming ink 11′ is less susceptible to oxygen inhibition and canbe cured at lower energy; also, copolymerization comprising othermonomers can be promoted, and the three-dimensional shaped article 10can be given particularly high strength.

When the substantive section-forming ink 11′ comprises a polyether-basedaliphatic urethane (meth)acrylate oligomer, the three-dimensional shapedarticle 10 can be given higher levels of both strength and toughness.

When the substantive section-forming ink 11′ comprises2-hydroxy-3-phenoxypropyl (meth)acrylate, the substantivesection-forming ink 11′ possesses flexibility and the elongation atbreak can be improved.

When the substantive section-forming ink 11′ comprises4-hydroxybutyl(meth)acrylate, then the adhesion to PMMA or PEMAparticles, silica particles, metal particles, and the like is improvedand the three-dimensional shaped article 10 can be given particularlyhigh strength.

In a case where the substantive section-forming ink 11′ comprises theaforementioned specific curing components (one or more species selectedfrom the group consisting of 2-(2-vinyloxyethoxy) ethyl (meth)acrylate,polyether-based aliphatic urethane (meth)acrylate oligomer,2-hydroxy-3-phenoxypropyl(meth)acrylate, and4-hydroxybutyl(meth)acrylate), then the proportion of these specificcuring components with respect to the total curing componentsconstituting the substantive section-forming ink 11′ is preferably 80mass % or higher, more preferably 90 mass % or higher, even morepreferably 100 mass %. This causes the above such effects to be moreprominently exhibited.

The content ratio of the curing components in the substantivesection-forming ink 11′ is preferably 80 to 97 mass %, more preferably85 to 95 mass %.

This makes it possible to impart particularly excellent mechanicalstrength to the three-dimensional shaped article 10 that is ultimatelyobtained. The three-dimensional shaped article 10 can also be givenparticularly excellent productivity.

(Polymerization Initiator)

Preferably, the substantive section-forming ink 11′ comprises apolymerization initiator.

This makes it possible to accelerate the speed of curing of thesubstantive section-forming ink 11′ during the manufacture of thethree-dimensional shaped article 10, and makes it possible to give thethree-dimensional shaped article 10 particularly excellent productivity.

Examples of polymerization initiators that can be used include aphoto-radical polymerization initiator (an aromatic ketone, acylphosphine oxide compound, aromatic onium salt compound, organicperoxide, thio compound (a thioxanthone compound, a thiophenylgroup-containing compound, or the like), a hexaaryl biimidazolecompound, a ketoxime ester compound, a borate compound, an aziniumcompound, a metallocene compound, an active ester compound, a compoundhaving a carbon-halogen bond, an alkylamine compound, or the like) or aphoto-cationic polymerization initiator. Specific examples includeacetophenone, acetophenonebenzylketal, 1-hydroxycyclohexyl phenylketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone,benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole,3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone,4,4′-diamino-benzophenone, Michler's ketone, benzoin isopropyl ether,benzoin ethyl ether, benzyl dimethyl ketal,1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one,2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanethone,diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone,2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one,bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide,2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide, 2,4-diethylthioxantone,and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphineoxide,from which one species can be selected for use, or two or more speciescan be combined for use.

Of these, a preferable polymerization initiator constituting thesubstantive section-forming ink 11′ is one that comprisesbis(2,4,6-trimethylbenzoyl)-phenyl phosphoneoxide and/or2,4,6-trimethylbenzoyl-diphenyl-phosphoneoxide.

Comprising such a polymerization initiator makes it possible to cure thesubstantive section-forming ink 11′ at a more appropriate speed ofcuring, causes the matte-toned outer appearance to be more reliablyobtained in the three-dimensional shaped article 10, and makes itpossible to give the three-dimensional shaped article 10 particularlyexcellent productivity.

The substantive section 11 that is formed by curing the substantivesection-forming ink 11′ can also be given particularly excellentmechanical strength and shape stability. As a result, thethree-dimensional shaped article 10 can be given particularly excellentstrength, durability, and reliability.

In particular, along with the sacrificial layer-forming ink 12′, whichshall be described below, when the substantive section-forming ink 11′comprises bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide as apolymerization initiator, then the speeds of curing of the substantivesection-forming ink 11′ and the sacrificial layer-forming ink 12′ can bemore suitably controlled and the matte-toned outer appearance is evenmore reliably obtained in the three-dimensional shaped article 10. Thethree-dimensional shaped article 10 can also be given even moreexcellent productivity.

In a case where the substantive section-forming ink 11′, along with thesacrificial layer-forming ink 12′ described below, is one that comprisesbis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide as a polymerizationinitiator, then the content ratio of thebis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide in the substantivesection-forming ink 11′ is preferably higher than the content ratio ofthe bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide in the sacrificiallayer-forming ink 12′.

This makes it possible to cure the substantive section-forming ink 11′and the sacrificial layer-forming ink 12′ each at a more suitable speed,and causes the matte-toned outer appearance to be even more reliablyobtained in the three-dimensional shaped article 10.

The content ratio of the polymerization initiator in the substantivesection-forming ink 11′ is not particularly limited but is preferablyhigher than the content ratio of the polymerization initiator in thesacrificial layer-forming ink 12′.

This makes it possible to cure the substantive section-forming ink 11′and the sacrificial layer-forming ink 12′ each at a more suitable speed,and causes the matte-toned outer appearance to be even more reliablyobtained in the three-dimensional shaped article 10.

Also, for example, adjusting the treatment conditions in the curing stepmakes it possible to give the sacrificial layers 12 a comparativelylower degree of polymerization even while giving the substantive section11 an adequately high degree of curing after the end of the curing step.This results in making it possible to more easily remove the sacrificiallayers 12 in the sacrificial layer removal step and making it possibleto give the three-dimensional shaped article 10 particularly excellentproductivity.

So doing is also preferable from the viewpoint of conserving energy,because there is no need to increase more than necessary the amount ofenergy rays to be irradiated.

In particular, where the content ratio of the polymerization initiatorin the substantive section-forming ink 11′ is X₁ [mass %] and thecontent ratio of the polymerization initiator in the sacrificiallayer-forming ink 12′ is X₂ [mass %], the relationship 1.05≦X₂/X₂≦2.0 ispreferably satisfied; more preferably, the relationship 1.1≦X₁/X₂≦1.5 issatisfied.

This makes it possible for the substantive section-forming ink 11′ andthe sacrificial layer-forming ink 12′ to each be cured at a moreappropriate speed, causes the matte-toned outer appearance to be evenmore reliably obtained in the three-dimensional shaped article 10, andmakes it possible to give the three-dimensional shaped article 10 evenmore excellent productivity.

As a specific value for the content ratio of the polymerizationinitiator in the substantive section-forming ink 11′, 3.0 to 18 mass %is preferable; 5.0 to 15 mass % is even more preferable.

This makes it possible to cure the substantive section-forming ink 11′at a more appropriate speed of curing, causes the matte-toned outerappearance to be more reliably obtained in the three-dimensional shapedarticle 10, and makes it possible to provide the three-dimensionalshaped article 10 with particularly excellent productivity.

The substantive section 11 that is formed by curing the substantivesection-forming ink 11′ can also be given particularly excellentmechanical strength and shape stability. As a result, thethree-dimensional shaped article 10 can be given particularly excellentstrength, durability, and reliability.

A preferred specific example of the blending ratio (an ink composition,which excludes “other components” described below) of the curable resinand polymerization initiator in the substantive section-forming ink 11′shall be illustrated below, but it shall be readily understood that thecomposition of the substantive section-forming ink in the presentinvention is in no way limited to what is described below.

BLENDING RATIO EXAMPLE

2-(2-vinyloxyethoxy) ethyl acrylate: 32 parts by mass

Polyether-based aliphatic urethane acrylate oligomer: 10 parts by mass

2-hydroxy-3-phenoxypropylacrylate 13.75 parts by mass

Dipropyleneglycol diacrylate: 15 parts by mass

4-hydroxybutylacrylate: 20 parts by mass

Bis(2,4,6-trimethylbenzoyl)phenylphoshine oxide: 5 parts by mass

2,4,6-trimethylbenzoyl diphenyl phosphone oxide: 4 parts by mass

In a case of the above such formulation, the above such effects are moreprominently exhibited.

(Other Components)

In addition, the substantive section-forming ink 11′ may also comprisecomponents other than those described above.

Examples of such components include a variety of coloring agents such asa pigment or dye; a dispersing agent; a surfactant; a sensitizer; apolymerization accelerator; a solvent; a penetration enhancer; a wettingagent (humectant); a fixing agent; an anti-fungal agent; a preservative;an antioxidant; an ultraviolet ray absorption agent; a chelating agent;a pH adjusting agent; a thickener; a filler; an aggregation inhibitor,an anti-foaming agent; and the like.

In particular, when the substantive section-forming ink 11′ comprises acoloring agent, this makes it possible to obtain a three-dimensionalshaped article 10 that has been colored to a color corresponding to thecolor of the coloring agent.

In particular, comprising a pigment as a coloring agent makes itpossible to give the substantive section-forming ink 11′ and thethree-dimensional shaped article 10 favorable light resistance. For thepigment, it would be possible to use an inorganic pigment or an organicpigment.

Examples of inorganic pigments include: carbon blacks (C.I. PigmentBlack 7) such as furnace black, lamp black, acetylene black and channelblack; iron oxide, or titanium oxide; from which one kind can beselected for use, or two or more kinds can be combined for use.

Of these inorganic pigments, titanium oxide is preferable because of thepreferable white color exhibited thereby.

Examples of inorganic pigments include: an azo pigment such as aninsoluble azo pigment, a condensed azo pigment, azo lake, or chelate azopigment; a polycyclic pigment such as a phthalocyanine pigment, aperylene or perynone pigment, an anthraquinone pigment, a quinacridonepigment, a dioxane pigment, a thioindigo pigment, an isoindolinonepigment, or a quinophthalone pigment; dye chelate (for example, a basicdye chelate or an acidic dye chelate, or the like); a color lake (abasic dye lake or an acidic dye lake); a nitro pigment; a nitrosopigment; aniline black; or a daylight fluorescent pigment; it would alsobe possible to use one species selected from these or a combination oftwo or more species selected from these.

More specifically, examples of carbon blacks that are used as pigmentsfor the color black include: No. 2300, No. 900, MCF88, No. 33, No. 40,No. 45, No. 52, MA7, MA8, MA100, No. 2200B, and the like (MitsubishiChemical); Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255,Raven 700, and the like (Carbon Columbia); Regal 400R, Regal 330R, Regal660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900,Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, and the like(Cabot Japan); and Color Black FW1, Color Black FW2, Color Black FW2V,Color Black FW18, Color Black FW200, Color Black 5150, Color Black 5160,Color Black 5170, Printex 35, Printex U, Printex V, Printex 140U,Special Black 6, Special Black 5, Special Black 4A, Special Black 4(Degussa).

Examples of pigments for the color white include C.I. Pigment White 6,8, and 21.

Examples of pigments for the color yellow include C.I. Pigment Yellow 1,2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55,65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114,117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 167, 172,and 180.

Examples of pigments for the color magenta include C.I. Pigment Red 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23,30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 88,112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176,177, 178, 179, 184, 185, 187, 202, 209, 219, 224, and 245, or C.I.Pigment Violet 19, 23, 32, 33, 36, 38, 43, and 50.

Examples of pigments for the color cyan include C.I. Pigment Blue 1, 2,3, 15, 15:1, 15:2, 15:3, 15:34, 15:4, 16, 18, 22, 25, 60, 65, 66, andC.I. Vat Blue 4 and 60.

Examples of pigments other than those mentioned above include C.I.Pigment Green 7 and 10, C.I. Pigment Brown 3, 5, 25, and 26, and C.I.Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, and63.

In a case where the substantive section-forming ink 11′ comprises apigment, then the mean particle size of the pigment is preferably 300 nmor smaller, more preferably 50 to 250 nm.

This makes it possible to give the substantive section-forming ink 11′particularly excellent discharge stability and to give the pigment inthe substantive section-forming ink 11′ particularly excellentdispersion stability, and makes it possible to form an image of moreexcellent image quality.

Examples of dyes include an acidic dye, a direct dye, a reactive dye, ora basic dye; it would also be possible to use one species selected fromthese or a combination of two or more species selected from these.

Specific examples of dyes include C.I. Acid Yellow 17, 23, 42, 44, 79,and 142, C.I. Acid Red 52, 80, 82, 249, 254, and 289, C.I. Acid Blue 9,45, and 249, C.I. Acid Black 1, 2, 24, and 94, C.I. Food Black 1 and 2,C.I. Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, and173, C.I. Direct Red 1, 4, 9, 80, 81, 225, and 227, C.I. Direct Blue 1,2, 15, 71, 86, 87, 98, 165, 199, and 202, C.I. Direct Black 19, 38, 51,71, 154, 168, 171, and 195, C.I. Reactive Red 14, 32, 55, 79, and 249,and C.I. Reactive Black 3, 4, and 35.

In a case where the substantive section-forming ink 11′ comprises acoloring agent, then the content ratio of the coloring agent in thesubstantive section-forming ink 11′ is preferably 1 to 20 mass %. Thisproduces particularly excellent masking and color reproducibility.

In particular, in a case where the substantive section-forming ink 11′comprises titanium oxide as a coloring agent, then the content ratio ofthe titanium oxide in the substantive section-forming ink 11′ ispreferably 12 to 18 mass %, more preferably 14 to 16 mass %. Thisproduces particularly excellent masking.

In a case where the substantive section-forming ink 11′ comprises apigment, then when a dispersing agent is also included, thedispersibility of the pigment can be further improved.

Though not particularly limited, examples of dispersing agents includedispersing agents that are commonly used to prepare pigment dispersions,such as polymeric dispersing agents.

Specific examples of polymeric dispersing agents include those composedmainly of one or more species from among polyoxyalkylene polyalkylenepolyamine, vinyl-based polymers and copolymers, acrylic polymers andcopolymers, polyester, polyamide, polyimide, polyurethane, amino-basedpolymers, silicon-containing polymers, sulfur-containing polymers,fluorine-containing polymers, and epoxy resins.

Examples of commercially available forms of polymeric dispersing agentsinclude Ajinomoto Fine-Techno's Ajisper series, the Solsperse series(Solsperse 36000 and the like) available from Noveon, BYK's Disperbykseries, and Kusumoto Chemicals' Disparlon series.

When the substantive section-forming ink 11′ comprises a surfactant, theabrasion resistance of the three-dimensional shaped article 10 can befurther improved.

Though not particularly limited, examples of what can be used as asurfactant include polyester-modified silicone or polyether-modifiedsilicone serving as a silicone-based surfactant; of these, it ispreferable to use polyether-modified polydimethylsiloxane orpolyester-modified polydimethylsiloxane.

Specific examples of surfactants include BYK-347, BYK-348, and BYK-UV3500, 3510, 3530, and 3570 (which are trade names of BYK).

The substantive section-forming ink 11′ may also comprise a solvent.

This makes it possible to suitably adjust the viscosity of thesubstantive section-forming ink 11′, and makes it possible to give thesubstantive section-forming ink 11′ particularly excellent stability ofdischarge by inkjet format even when the substantive section-forming ink11′ comprises high-viscosity components.

Examples of solvents include: (poly)alkylene glycol monoalkyl etherssuch as ethylene glycol monomethyl ether, ethylene glycol monoethylether, propylene glycol monomethyl ether, and propylene glycol monoethylether; acetic acid esters such as ethyl acetate, n-propyl acetate,isopropyl acetate, n-butyl acetate, and isobutyl acetate; aromatichydrocarbons such as benzene, toluene, and xylene; ketones such asmethyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl-n-butylketone, diisopropyl ketone, and acetylacetone; and alcohols such asethanol, propanol, and butanol; it would also be possible to use onespecies selected from these or a combination of two or more speciesselected from these.

The viscosity of the substantive section-forming ink 11′ is preferably10 to 30 mPa·s, more preferably 15 to 25 mPa·s.

This makes it possible to give the substantive section-forming ink 11′particularly excellent stability of discharge by inkjet. In the presentspecification, “viscosity” refers to a value measured at 25° C. using anE-type viscometer (Visconic ELD made by Tokyo Keiki).

A plurality of kinds of substantive section-forming ink 11′ may be usedin the manufacture of the three-dimensional shaped article 10.

For example, a substantive section-forming ink 11′ (color ink) thatcomprises a coloring agent and a substantive section-forming ink 11′(clear ink) that does not comprise a coloring agent may both be used.

This makes it possible, for example, to use the substantivesection-forming ink 11′ that comprises the coloring agent as asubstantive section-forming ink 11′ applied to a region where the colortone is affected in terms of the outer appearance of thethree-dimensional shaped article 10 and to use the substantivesection-forming ink 11′ that does not comprise a coloring agent as asubstantive section-forming ink 11′ applied to a region where the colortone is not affected in terms of the outer appearance of thethree-dimensional shaped article 10, and is advantageous due in part toreducing the costs of producing the three-dimensional shaped article 10.

Also, a plurality of kinds of substantive section-forming ink 11′ may beused in combination so as to provide a region (coating layer) formedusing the substantive section-forming ink 11′ that does not comprise acoloring agent on the outer surface of a region formed using thesubstantive section-forming ink 11′ that does comprise a coloring agent,in the three-dimensional shaped article 10 that is ultimately obtained.

This makes it possible to more suitably render the matte-toned texture.The substantive section 11 that comprises the coloring agent (inparticular, pigment) is more brittle and prone to scratches, chipping,and the like than the substantive section 11 that does not comprise thecoloring agent, but providing the region (coating layer) formed usingthe substantive section-forming ink 11′ that does not comprise thecoloring agent makes it possible to effectively prevent the occurrenceof such problems. Changes in the color tone of the three-dimensionalshaped article 10 can also be effectively prevented and suppressed evenin a case where long-term use of the three-dimensional shaped article 10causes the surface to become worn.

Also, for example, a plurality of kinds of substantive section-formingink 11′ that comprise coloring agents of different compositions may beused.

This makes it possible to broaden the color reproduction range that canbe rendered, using these combinations of substantive section-forming ink11′.

In a case where a plurality of kinds of substantive section-forming ink11′ are used, it is preferable to use at least an indigo purple (cyan)substantive section-forming ink 11′, a red purple (magenta) substantivesection-forming ink 11′, and a yellow substantive section-forming ink11′.

This makes it possible to further broaden the color reproduction rangethat can be rendered, using these combinations of substantivesection-forming ink 11′.

Combined use of a white substantive section-forming ink 11′ withsubstantive section-forming inks 11′ of other colors also produces thefollowing effects.

Namely, the three-dimensional shaped article 10 that is ultimatelyobtained can be endowed with a first region to which the whitesubstantive section-forming ink 11′ is applied and a region (secondregion) to which a substantive section-forming ink 11′ of that iscolored (in particular, chromatic color) a color other than white isapplied, provided on the outer surface side from the first region. Thismakes it possible for the first region to which the white substantivesection-forming ink 11′ is applied to exhibit masking, and makes itpossible to further raise the chroma of the three-dimensional shapedarticle 10.

Also, the aforementioned effect where the matte-toned texture isobtained and the effect where the chroma is increased actsynergistically together, making it possible to give thethree-dimensional shaped article 10 a particularly excellent aestheticappearance (aesthetic).

<Sacrificial Layer-Forming Ink>

The sacrificial layer-forming ink 12′ comprises at least a curable resin(curing component).

(Curable Resin)

Examples of the curable resin (curing component) constituting thesacrificial layer-forming ink 12′ include similar ones to those curableresins (curing components) illustratively exemplified as the constituentcomponent of the substantive section-forming ink 11′.

In particular, the curable resin (curing component) constituting thesacrificial layer-forming ink 12′ and the aforementioned curable resin(curing component) constituting the substantive section-forming ink 11′are preferably cured by the same kind of energy ray.

This makes it possible to effectively prevent the configuration of theapparatus for manufacturing a three-dimensional shaped article frombecoming complicated, and makes it possible to give thethree-dimensional shaped article 10 particularly excellent productivity.The surface shape of the three-dimensional shaped article 10 can also bemore reliably controlled.

Of the variety of curing components, it is particularly preferable forthe sacrificial layer-forming ink 12′ to comprise one or more kindsselected from the group constituting of tetrahydrofurfuryl(meth)acrylate, ethoxyethoxy ethyl(meth)acrylate, polyethylene glycoldi(meth)acrylate, and (meth)acryloylmorpholine.

This makes it possible to cure the sacrificial layer-forming ink 12′ ata more appropriate curing speed, causes the matte-toned outer appearanceto be more reliably obtained in the three-dimensional shaped article 10,and makes it possible to give the three-dimensional shaped article 10particularly excellent productivity.

The sacrificial layers 12 that are formed by curing the sacrificiallayer-forming ink 12′ can also be given particularly excellentmechanical strength and stability of shape. As a result, during themanufacture of the three-dimensional shaped article 10, the sacrificiallayer 12 of the lower layer (first layer) can more suitably support thesubstantive section-forming ink 11′ for forming the upper layer (secondlayer). Therefore, unintended deformation (in particular, sagging andthe like) of the substantive section 11 can be suitably prevented (thesacrificial layer 12 of the first layer functions as a supportmaterial), and the three-dimensional shaped article 10 that isultimately obtained can be given particularly excellent dimensionalaccuracy.

In particular, when the sacrificial layer-forming ink 12′ comprises(meth)acryloylmorpholine, the following effects are obtained.

Namely, (meth)acryloylmorpholine is such that the solubility in avariety of solvents is high in a state (polymer of(meth)acryloylmorpholine in an incompletely cured state) where curing isnot complete even in a case where the curing reaction has advanced. Assuch, the sacrificial layers 12 can be selectively, reliably, andefficiently removed even while defects are being more effectivelyprevented from occurring in the substantive section 11 in theaforementioned sacrificial layer removal step. As a result, thethree-dimensional shaped article 10 of the desired form can be obtainedat higher reliability and with favorable productivity.

When the sacrificial layer-forming ink 12′ comprises tetrahydrofurfuryl(meth)acrylate, the flexibility after curing can be more suitablymaintained, the matte-toned texture is more effectively formed on thesurface of the substantive section 11, and a gel form can be more easilyachieved in the treatment by liquid for removing the sacrificial layers12, thus further raising the efficiency of removing the sacrificiallayers 12.

When the sacrificial layer-forming ink 12′ comprises ethoxyethoxy ethyl(meth)acrylate, then the tackiness more readily remains even aftercuring, the matte-toned texture is more effectively formed on thesurface of the substantive section 11, and the efficiency of removingthe sacrificial layers 12 can be raised in the treatment by liquid forremoving the sacrificial layers 12.

When the sacrificial layer-forming ink 12′ comprises polyethylene glycoldi(meth)acrylate, then in a case where the liquid for removing thesacrificial layers has water as the principal component, the solubilityin the liquid can be raised and the sacrificial layers 12 can be moreeasily removed.

In a case where the sacrificial layer-forming ink 12′ comprises theaforementioned specific curing component (one or more kinds selectedfrom the group consisting of tetrahydrofurfuryl (meth)acrylate,ethoxyethoxy ethyl (meth)acrylate, polyethylene glycol di(meth)acrylate,and (meth)acryloylmorpholine), then the proportion of the specificcuring component with respect to the total curing componentsconstituting the sacrificial layer-forming ink 12′ is preferably 80 mass% or more, more preferably 90 mass % or more, even more preferably 100mass %. This causes the effects described above to be more prominentlyexerted.

The content ratio of the curing component in the sacrificiallayer-forming ink 12′ is preferably 83 to 98.5 mass %, more preferably87 to 95.4 mass %.

This makes it possible to endow the sacrificial layers 12 that areformed with particularly excellent shape stability, makes it possible tomore effectively prevent the underlying layers 1 from experiencingunintended deformation in a case where the layers 1 have been stackedduring the manufacture of the three-dimensional shaped article 10, andmakes it possible to more suitably support the upper layer 1. As aresult, the three-dimensional shaped article 10 that is ultimatelyobtained can be given particularly excellent dimensional accuracy. It isalso possible to give the three-dimensional shaped article 10particularly excellent productivity.

(Polymerization Initiator)

The sacrificial layer-forming ink 12′ preferably comprises apolymerization initiator.

This makes it possible to appropriately increase the speed of curing ofthe sacrificial layer-forming ink 12′ during the manufacture of thethree-dimensional shaped article 10, and makes it possible to give thethree-dimensional shaped article 10 particularly excellent productivity.

This also makes it possible to endow the sacrificial layers 12 that areformed with particularly excellent shape stability, makes it possible tomore effectively prevent the underlying layers 1 from experiencingunintended deformation in a case where the layers 1 have been stackedduring the manufacture of the three-dimensional shaped article 10, andmakes it possible to more suitably support the upper layer 1. As aresult, the three-dimensional shaped article 10 that is ultimatelyobtained can be given particularly excellent dimensional accuracy.

Examples of the polymerization initiator constituting the sacrificiallayer-forming ink 12′ are similar to the polymerization initiatorsillustratively exemplified as a constituent component of the substantivesection-forming ink 11′.

In particular, it is preferable for the sacrificial layer-forming ink12′ to comprise bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide and/or2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide as the polymerizationinitiator.

Comprising such a polymerization initiator makes it possible to cure thesacrificial layer-forming ink 12′ at a more appropriate curing speed,causes the matte-toned outer appearance to be more reliably obtained inthe three-dimensional shaped article 10, and makes it possible to givethe three-dimensional shaped article 10 particularly excellentproductivity.

The sacrificial layers 12 that are formed by curing the sacrificiallayer-forming ink 12′ can also be given particularly excellentmechanical strength and stability of shape. As a result, during themanufacture of the three-dimensional shaped article 10, the sacrificiallayer 12 of the lower layer (first layer) can more suitably support thesubstantive section-forming ink 11′ for forming the upper layer (secondlayer). Therefore, unintended deformation (in particular, sagging andthe like) of the substantive section 11 can be suitably prevented (thesacrificial layer 12 of the first layer functions as a supportmaterial), and the three-dimensional shaped article 10 that isultimately obtained can be given particularly excellent dimensionalaccuracy.

In particular, when the sacrificial layer-forming ink 12′, along withthe substantive section-forming ink 11′, comprisesbis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide as a polymerizationinitiator, then the curing speeds for the substantive section-formingink 11′ and the sacrificial layer-forming ink 12′ can be more suitablycontrolled, and the matte-toned outer appearance is more reliablyobtained in the three-dimensional shaped article 10. Thethree-dimensional shaped article 10 can also be given even moreexcellent productivity.

As a specific value for the content ratio of the polymerizationinitiator in the sacrificial layer-forming ink 12′, 1.5 to 17 mass % ispreferable; 4.6 to 13 mass % is even more preferable.

This makes it possible to cure the sacrificial layer-forming ink 12′ ata more appropriate curing speed, causes the matte-toned outer appearanceto be more reliably obtained in the three-dimensional shaped article 10,and makes it possible to give the three-dimensional shaped article 10particularly excellent productivity.

The sacrificial layers 12 that are formed by curing the sacrificiallayer-forming ink 12′ can also be given particularly excellentmechanical strength and stability of shape. As a result, during themanufacture of the three-dimensional shaped article 10, the sacrificiallayer 12 of the lower layer (first layer) can more suitably support thesubstantive section-forming ink 11′ for forming the upper layer (secondlayer). Therefore, unintended deformation (in particular, sagging andthe like) of the substantive section 11 can be suitably prevented (thesacrificial layer 12 of the first layer functions as a supportmaterial), and the three-dimensional shaped article 10 that isultimately obtained can be given particularly excellent dimensionalaccuracy.

A preferred specific example of the blending ratio (an ink composition,which excludes “other components” described below) of the curable resinand polymerization initiator in the sacrificial layer-forming ink 12′shall be illustrated below, but it shall be readily understood that thecomposition of the sacrificial layer-forming ink in the presentinvention is in no way limited to what is described below.

Blending Ratio Example 1

Tetrahydrofurfuryl acrylate: 36 parts by mass

Ethoxyethoxy ethyl acrylate: 55.75 parts by mass

Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide: 3 parts by mass

2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide: 5 parts by mass

Blending Ratio Example 2

Dipropyleneglycol diacrylate: 37 parts by mass

Polyethylene glycol (400) diacrylate: 55.85 parts by mass

Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide: 3 parts by mass

2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide: 4 parts by mass

Blending Ratio Example 3

Tetrahydrofurfuryl acrylate: 36 parts by mass

Acryloylmorpholine: 55.75 parts by mass

Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide: 3 parts by mass

2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide: 5 parts by mass

In a case of the above such formulation, the above such effects are moreprominently exhibited.

(Other Components)

In addition, the sacrificial layer-forming ink 12′ may also comprisecomponents other than those described above. Examples of such componentsinclude a variety of coloring agents such as a pigment or dye; adispersing agent; a surfactant; a sensitizer; a polymerizationaccelerator; a solvent; a penetration enhancer; a wetting agent(humectant); a fixing agent; an anti-fungal agent; a preservative; anantioxidant; an ultraviolet ray absorption agent; a chelating agent; apH adjusting agent; a thickener; a filler; an aggregation inhibitor; ananti-foaming agent; and the like.

In particular, when the sacrificial layer-forming ink 12′ comprises acoloring agent, this improves the visibility of the sacrificial layers12, making it possible to more reliably prevent at least a part of thesacrificial layers from remaining in an unintended manner in thethree-dimensional shaped article 10 that is ultimately obtained.

Examples of coloring agents constituting the sacrificial layer-formingink 12′ are similar to the coloring agents illustratively exemplified asa constituent component of the substantive section-forming ink 11′, butthe coloring agent is preferably a different color than the color (thecolor that is to be visible in terms of the outer appearance of thethree-dimensional shaped article 10) of the substantive section 11,which overlaps with the sacrificial layers 12 formed by the sacrificiallayer-forming ink 12′ when observed from the normal direction of thesurface of the three-dimensional shaped article 10. This causes theeffects described above to be more prominently exerted.

In a case where the sacrificial layer-forming ink 12′ comprises apigment, then when a dispersing agent is also included, thedispersibility of the pigment can be further improved. Examples of thedispersing agent constituting the sacrificial layer-forming ink 12′ aresimilar to the dispersing agents illustratively exemplified as aconstituent component of the substantive section-forming ink 11′.

The viscosity of the sacrificial layer-forming ink 12′ is preferably 10to 30 mPa·s, more preferably 15 to 25 mPa·s.

This makes it possible to give the sacrificial layer-forming ink 12′particularly excellent stability of discharge by inkjet.

A plurality of kinds of sacrificial layer-forming ink 12′ may be used inthe manufacture of the three-dimensional shaped article 10.

For example, two or more kinds of sacrificial layer-forming ink 12′ thathave mutually different viscoelasticities during curing of thesubstantive section-forming ink 11′ can be used.

This makes it possible for the three-dimensional shaped article 10 thatis ultimately obtained to have a plurality of regions at which thedegree of matte is different. As a result, it becomes possible to rendera more complex outer appearance, and the three-dimensional shapedarticle 10 can be given a particularly excellent aesthetic appearance(aesthetics), luxuriousness, and the like.

It is also conceivable, for example, to use two or more kinds ofsubstantive section-forming ink 11′ having each having a differentviscoelasticity during curing in order to obtain such effects, but insuch a case, there is the possibility that problems such as when thephysical properties at each of the sites of the three-dimensional shapedarticle 10 that is ultimately obtained are different in an unintendedmanner could occur; by contrast, in a case where a plurality of kinds ofsacrificial layer-forming ink 12′ are used, it is possible to obtain theaforementioned effects even while reliably preventing the occurrence ofsuch problems.

The ink set of the present invention need only be provided with at leastone kind of substantive section-forming ink (first ink) 11′ and at leastone kind of sacrificial layer-forming ink (second ink) 12′, but may alsobe provided with a third ink different therefrom.

Examples of the third ink include a sacrificial layer-forming ink notsatisfying the aforementioned conditions. Being provided with such athird ink makes it possible to endow the three-dimensional shapedarticle 10 with a region exhibiting the matte-toned texture and a regionexhibiting a texture other than matte-toned. As a result, it becomespossible to render a more complex outer appearance, and thethree-dimensional shaped article 10 can be given a particularlyexcellent aesthetic appearance (aesthetics), luxuriousness, and thelike.

According to the ink set of the present invention as described above,the three-dimensional shaped article having a matte-toned texture can bemanufactured stably and efficiently. Also, the yield of thethree-dimensional shaped article is improved and therefore the presentinvention is also advantageous in terms of reducing the costs ofmanufacturing the three-dimensional shaped article.

<<Three-Dimensional Shaped Article>>

The three-dimensional shaped article of the present invention can bemanufactured using the method of manufacture, apparatus formanufacturing a three-dimensional shaped article, and ink set asdescribed above. This makes it possible to provide a three-dimensionalshaped article having a matte-toned texture.

Use of the three-dimensional shaped article of the present invention isnot particularly limited, but examples include an ornamental article orpresented article such as a doll or figure, a medical device such as animplant, and the like.

The three-dimensional shaped article of the present invention may alsobe applied to prototypes, mass-produced goods, and custom-made goods.

The three-dimensional shaped article of the present invention may alsobe a model (for example, a model of (an automobile, a motorcycle, aboat, an airplane, or another such vehicle, a building, an animal, aplant, or another such living thing, a stone or another such natural(non-living) object, a variety of food products, and the like).

With a model, it is preferable to faithfully reproduce the texture andthe like possessed by the original, but with a three-dimensional shapedarticle manufactured using a conventional lamination method, it has notbeen possible to respond sufficiently to such a need. By contrast, withthe present invention, it is possible to suitable render a matte tone,which has conventionally been especially difficult to render. As such,the effects of the present invention are more prominently exhibited in acase where the present invention is applied to a model.

A preferred embodiment of the present invention have been describedabove, but the present invention is in no way limited thereto.

For example, the embodiment described above centers on describing a casewhere the substantive section-forming ink and the sacrificiallayer-forming ink are discharged by inkjet, but the substantivesection-forming ink and the sacrificial layer-forming ink may be appliedwith another method (for example, another print method).

In the method of manufacture of the present invention, a pre-treatmentstep, an intermediate treatment step, and a post-treatment step may becarried out as needed.

Examples of the pre-treatment step include a step for cleaning thestage, and the like.

Examples of the post-treatment step include a washing step, a shapeadjustment step for deburring and the like, an additional curing stepfor increasing the degree of curing of the curable resin constitutingthe substantive section, and the like.

An additional example of the post-treatment step may have a step forperforming a roughening treatment for increasing the matte tone of thethree-dimensional shaped article. As described above, in the presentinvention, when the substantive section-forming ink and the sacrificiallayer-forming ink satisfy a predetermined relationship as regardsviscoelasticity, this makes it possible to endow the surface with a highmatte appearance; therefore, even in a case where such a post-treatmentis performed, the post-treatment can be easily performed in a shortperiod of time, and therefore the three-dimensional shaped article canbe given excellent productivity. The effect from when the substantivesection-forming ink and the sacrificial layer-forming ink satisfy apredetermined relationship as regards viscoelasticity and the effectfrom performing the post-treatment step act synergistically together,making it possible to obtain an excellent matte-toned outer appearancethat could not conventionally be achieved, even were the post-treatmentstep to be performed.

The present invention may also be applied to a powder lamination method(namely, a method for obtaining a three-dimensional shaped article inthe form of a laminate having a plurality of layers to which a curedsection is provided, by repeatedly carrying out a series of operationsthat are to use a powder to form a layer, and apply a curable ink to apredetermined site of the layer to form the cured section).

General Interpretation of Terms

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. Finally, terms of degree such as“substantially”, “about” and “approximately” as used herein mean areasonable amount of deviation of the modified term such that the endresult is not significantly changed. For example, these terms can beconstrued as including a deviation of at least ±5% of the modified termif this deviation would not negate the meaning of the word it modifies.

While only a selected embodiment has been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. Furthermore, the foregoing descriptions of theembodiment according to the present invention are provided forillustration only, and not for the purpose of limiting the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A three-dimensional shaped article manufacturingmethod for manufacturing a three-dimensional shaped article bylaminating layers formed by discharging and curing inks including acurable resin, the method comprising: applying a substantivesection-forming ink to a region that forms the three-dimensional shapedarticle; and applying a sacrificial layer-forming ink for forming asacrificial layer to a region that is adjacent to a region that forms anoutermost layer of the three-dimensional shaped article and on a surfaceside of the outermost layer, a viscoelasticity of the sacrificiallayer-forming ink during curing of the substantive section-forming inkbeing less than a viscoelasticity of the substantive section-forming inkduring curing of the substantive section-forming ink.
 2. Thethree-dimensional shaped article manufacturing method as set forth inclaim 1, further comprising removing the sacrificial layer from aprovisional molded article obtained by curing the substantivesection-forming ink and the sacrificial layer-forming ink.
 3. Thethree-dimensional shaped article manufacturing method as set forth inclaim 1, wherein the sacrificial layer-forming ink includes one or morespecies selected from the group consisting of tetrahydrofurfuryl(meth)acrylate, ethoxyethoxy ethyl (meth)acrylate, polyethylene glycoldi(meth)acrylate, and (meth)acryloylmorpholine.
 4. The three-dimensionalshaped article manufacturing method as set forth in claim 1, wherein thesubstantive section-forming ink includes one or more species selectedfrom the group consisting of 2-(2-vinyloxyethoxy) ethyl (meth)acrylate,polyether-based aliphatic urethane (meth)acrylate oligomer,2-hydroxy-3-phenoxypropyl(meth)acrylate, and4-hydroxybutyl(meth)acrylate.
 5. The three-dimensional shaped articlemanufacturing method as set forth in claim 1, wherein the substantivesection-forming ink and the sacrificial layer-forming ink both include apolymerization initiator, a content ratio of the polymerizationinitiator in the substantive section-forming ink being higher than acontent ratio of the polymerization initiator in the sacrificiallayer-forming ink.
 6. The three-dimensional shaped article manufacturingmethod as set forth in claim 1, wherein the substantive section-formingink and the sacrificial layer-forming ink both includebis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide and/or2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide as a polymerizationinitiator.
 7. The three-dimensional shaped article manufacturing methodas set forth in claim 1, wherein a color ink containing a coloring agentand, in addition thereto, a colorless ink not containing a coloringagent are used as the substantive section-forming ink, the colorless inkbeing used upon formation of the region that forms the outermost layer,and the color ink being used upon formation of a region that is insidetherefrom.
 8. The three-dimensional shaped article manufacturing methodas set forth in claim 1, wherein a chromatic color ink and a white inkare used as a color ink containing a coloring agent, the white ink beingused upon formation of a region inside of a region formed using thechromatic color ink.
 9. The three-dimensional shaped articlemanufacturing method as set forth in claim 1, wherein a plurality ofdifferent types of the sacrificial layer-forming ink are used.
 10. Thethree-dimensional shaped article manufacturing method as set forth inclaim 1, wherein the sacrificial layer-forming ink is selectivelyapplied to a part of the region that is adjacent to the region thatforms the outermost layer of the three-dimensional shaped article and onthe surface side of the outermost layer.
 11. A three-dimensional shapedarticle manufacturing apparatus for manufacturing a three-dimensionalshaped article by laminating layers formed by discharging and curinginks including a curable resin, the apparatus comprising: a firstdischarge unit configured to discharge a substantive section-forming inkto a region that forms the three-dimensional shaped article; a seconddischarge unit configured to discharge a sacrificial layer-forming inkfor forming a sacrificial layer to a region that is adjacent to a regionthat forms an outermost layer of the three-dimensional shaped articleand on a surface side of the outermost layer; and a curing unitconfigured to cure the substantive section-forming ink and thesacrificial layer-forming ink, a viscoelasticity of the sacrificiallayer-forming ink during curing of the substantive section-forming inkbeing less than a viscoelasticity of the substantive section-forming inkduring curing of the substantive section-forming ink.
 12. An ink setused for manufacturing a three-dimensional shaped article by laminatinglayers formed by discharging and curing inks including a curable resin,the ink set comprising: a substantive section-forming ink applied to aregion that forms the three-dimensional shaped article; and asacrificial layer-forming ink applied to a region that is adjacent to aregion that forms an outermost layer of the three-dimensional shapedarticle and on a surface side of the outermost layer, a viscoelasticityof the sacrificial layer-forming ink during curing of the substantivesection-forming ink being less than a viscoelasticity of the substantivesection-forming ink during curing of the substantive section-formingink.
 13. A three-dimensional shaped article manufactured using thethree-dimensional shaped article manufacturing method as set forth inclaim
 1. 14. A three-dimensional shaped article manufactured using thethree-dimensional shaped article manufacturing apparatus as set forth inclaim
 11. 15. A three-dimensional shaped article manufactured using theink set as set forth in claim 12.